The NTCA puts installers of the Miami Sandwich on notice.

The Miami sandwich finally received the recognition it deserves; two pages in the NTCA Reference Manual outlining exactly why it is such a poor practice. Earlier in 2025 the NTCA Methods & Standards Committee appointed me to be part of a sub group led by Martin Howard of David Allen Company, to gather information related to the Miami Sandwich. This group also consisted of Rod Owen of CC Owen, Jim Whitfield of Mapei, Joseph Mattice of Schulter Systems, and Scott Carothers from the Ceramic Tile Education Foundation. Scott Conwell from the International Masonry Institute supplied a drawing that details all of the materials assembled in a Miami Sandwich. These gentleman brought a tremendous amount of knowledge and experience, and I thank them all for their time and efforts. Becky Serbin from the NTCA is the coordinator that helped bring us all together.

The document includes all of the reasons this practice leads to failure, but the aspect I felt was the most important was defining exactly what the Miami Sandwich is, and what it looks like. On April 28th, 2025 this document was approved by the NTCA Technical Committee. This was my first day on the technical committee, and this document had taken years to get to this point. There was a time when I tried to get peers in the tile industry to stop using the term Miami Sandwich. I felt the term was another dig at the state of Florida and it's poor contractor reputation. Ultimately It was a battle I couldn't win, the important battle was making sure contractors could identify and understand why the Miami Sandwich is such a poor practice.

The NTCA Reference Manual now includes information on the problematic practice of the Miami Sandwich.

The term Miami Sandwich has become synonymous with problematic practice, but when I speak with contractors, they aren't sure they would recognize it even if they saw it happening right in front of them. Worse still, some of them don't even realize it is something they do everyday. The document contains a drawing showing the profile of the materials, but more importantly photographs showing the sequence as the materials are placed. More than one general contractor has indicated to me over the years that this sequence is how he sees tile sub-contractors install stone and large format tile on a regular basis.

Unfortunately, many contractors are learning the hard way that the Miami Sandwich is a potential failure. When their luck runs out, they'll be dealing with dissatisfied customers at best, and hearing from attorneys when the situation is beyond practical repair. For a long time in the tile industry accountability has appeared non existent. The fact of the matter is homeowners are more informed than ever. Some of the knowledge they acquire online rivals that of so-called professionals. Customers simply do not stand for poor installations anymore, and they will hold contractors accountable. I am more than happy to help them understand what went wrong, and determine who is accountable.

While the TCNA and ANSI promote proper installation and material procedure, they don't identify incorrect or poor practice. This is to avoid confusion and make sure the things that are correct are always front and center. I firmly agree with this philosophy. The NTCA Reference Manual has always provided the answers on how to deal with pitfalls that come with installation errors. The NTCA provides the clarity in identifying improper technique, material application, specific environment considerations, and unacceptable methods of installation.

That is why the Miami Sandwich is the very next page following Spot Bonding. I cannot think of a more appropriate follow up to Spot Bonding than the Miami Sandwich. While it is not the guaranteed failure of Spot Bonding, it is almost as prevalent. For years, myself and other experts have had to explain the problem with the Miami Sandwich with no official document to stand behind. The reason for that is the NTCA committees don't take additions to the manual lightly. The failures with the Miami Sandwich are not one off mistakes. They are being found all over The United States.

With the addition of this document, new installers and even seasoned professionals can easily identify the Miami Sandwich. The excuse of I didn't know, or I've always done it like that is not gonna fly. The only way for the tile industry to grow and remain profitable is accountability.